Christmas frigatebird (Fregata andrewsi)

Also known as: Andrew's or Christmas Island frigatebird
  
French: Frégate d'Andrews
KingdomAnimalia
PhylumChordata
ClassAves
OrderPelecaniformes
FamilyFregatidae
GenusFregata (1)
SizeLength: 89 - 100 cm (2)

The Christmas frigatebird is classified as Critically Endangered (CR) on the IUCN Red List 2007 (1), and listed on Appendix I of CITES (3).

The Christmas frigatebird is a very large, mostly black seabird with a glossy green sheen to feathers of the head and back (4). Females are larger than males (5); they have a white breast and belly, a narrow white collar around the lower neck and a whitish bar across the upperwing (4). Males are dark all over apart from a white patch on the lower abdomen. They have a red gular pouch, which becomes more vibrant in the breeding season and is inflated during mating displays (4). Juveniles have more mottled feathers on their upper-parts (2), a pale fawn head, white throat and a russet necklace (4). They take around four years to gain adult plumage (4).

The Christmas frigatebird is found in the northeast Indian Ocean, these birds are only known to breed on Christmas Island (4). The distribution of birds at sea is not well documented but they may wander widely and are known from the coasts of Indonesia, Malaysia, Thailand (6) and northern Australia (4).

Although these birds do not settle on the water, they inhabit the open ocean, returning to land only to roost and breed. Both nesting and roosting occur on a small area of Christmas Island, in tall forest close to the shore (4). Nesting sites are preferentially in the lee of the prevailing southeast winds (4).

Males Christmas frigatebirds begin their mating displays in late December (4), inflating their scarlet throat pouches during courtship (2). Egg laying occurs between March and May and nests are positioned high in tall forest trees (6). A single egg is laid and both parents take it in turns during the 50 to 54 day incubation period; fledglings can remain dependant on their parents for six to seven months after their first flight (4).

The Christmas frigatebird feeds mainly on flying fish and cephalopods (such as squid), which are scooped from the surface of the water (6). A proportion of its food is obtained by harassing other seabirds such as red-footed boobies (Sula sula), until they are forced to regurgitate their meal (4).

Habitat destruction and human predation have been the major causes of population decline in the past (6); dust pollution from phosphate mine driers caused one major nesting site to be abandoned (4). Dust suppression equipment has since been installed and human predation has ceased since this species has been protected (4). Birds that have been displaced in the past may now be using sub-optimal habitat, which could pose a threat to their survival (4). The Christmas frigatebird is confined to a few breeding colonies on a single island and this, together with their low reproductive rate (4), makes the population alarmingly vulnerable to any chance event.

Christmas Island National Park was established in 1989 and contains two of the three current breeding populations of this species (5). Christmas frigatebirds are also protected outside of the park and by Migratory Bird Agreements between Australia and other countries (4). This species remains highly vulnerable however, and the close monitoring of breeding success and population size remains a high priority (4).

For more information on the Christmas frigatebird see:

Authenticated (22/10/02) by Max Orchard, Environment Australia.
http://www.ea.gov.au/index.html

  1. IUCN Red List (April, 2008)
    http://www.iucnredlist.org
  2. Erritzoe, J. (1993) The Birds of CITES and How to Identify Them. The Lutterworth Press, Cambridge.
  3. CITES (October, 2002)
    http://www.cites.org
  4. Orchard, M. (2002) Pers. comm.
  5. BirdLife International. (2000) Threatened Birds of the World. Lynx Edicions and BirdLife International, Barcelona and Cambridge.
  6. BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.